The anaerobic oxidation of ammonium (anammox) process has been observed in diverse terrestrial ecosystems, while the contribution of anammox to N2 production in paddy soils is not well documented. In this study, the anammox activity and the abundance and diversity of anammox bacteria were investigated to assess the anammox potential of 12 typical paddy soils collected in southern China. Anammox...

one of the crucial issues before the second cropping is having enough knowledge about the residue effect of first crop herbicides on second crops. this experiment was conducted to investigate the possible inhibitory effect of some selective paddy herbicides residues to second cropping. experimental factors were included common paddy herbicides (thiobencarb, butachlor, oxadiargyl, bensulfuronmet...

Paddy soils distribute widely from temperate to tropical regions, and are characterized by intensive nitrogen fertilization practices in China. Mounting evidence has confirmed the functional importance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in soil nitrification, but little is known about their biogeographic distribution patterns in paddy ecosystems. Here, we used barcoded pyrose...

Recent field studies in rice paddy fields in Japan and China have shown that N2O is emitted to the atmosphere not only after the application of nitrogen fertilisers under flooded conditions but also in a period from the final drainage to submergence in the following rice-growing season through nitrification or denitrification. Those results clearly indicate that CH4 and N2O emissions in rice pa...

This study aimed at the development of method of monitoring paddy rice planting applicable to areas located in the tropical humid climate region. The method was integrated with two steps of procedure. As the first step, we attempted to produce land use map which discriminated paddy field using multi-temporal Landsat data. In order to remove the effect of cloud cover, a new method of land use cl...

[1] Large-scale assessments of the potential for food production and its impact on biogeochemical cycling require the best possible information on the distribution of cropland. This information can come from ground-based agricultural census data sets and/ or spaceborne remote sensing products, both with strengths and weaknesses. Official cropland statistics for China contain much information on...

Research on change in land use and landscape pattern is the foundation for studies exploring natural and cultural landscape of a region. This study used GIS software and utilized topographic maps to examine the changes that occurred in the Oguraike floodplain, during the time points of 1888, 1909, 1961, and 2002. The Oguraike floodplain, which was dominated by the landscape of Oguraike Pond and...

A hydrogenotrophic motile methanogen was isolated from flooded Japanese paddy field soil. Anaerobic incubation of the paddy soil on H(2)-CO(2) at 20 degrees C led to the enrichment of symmetrically curved motile autofluorescent rods. The methanogenic strain TM20-1 isolated from the culture was halotolerant and utilized H(2)-CO(2), 2-propanol-CO(2), or formate as a sole methanogenic substrate. B...

Combined application of organic and inorganic amendments was known to play a significant role in improvement of soil properties. A field experiment was conducted to explore the effects of gypsum, farmyard manure and commercial humic acid application on the amelioration of salt affected (saline sodic) soil. During this study, soil pH, electrical conductivity, sodium adsorption ratio, responses o...

We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 smal...